1. Field of the Invention
The present invention relates to advanced turbulator arrangements for cooling microcircuits used in turbine engine components.
2. Prior Art
Turbulation devices have been used in cooling passageways as a way of increasing the heat being transferred. Typically, the previous trip-strip turbulation designs have centered around the designs shown in FIGS. 1 and 2. As shown in FIG. 1, a cooling passageway 10 having cooling fluid flowing in the direction 12 have had a pair of trip strips 14 and 16 forming a chevron design with the apex 18 of the chevron being along the flow direction 12 and the symmetrical axis 20 being parallel to the flow direction 12.
Referring now to FIG. 2, there is shown an alternative prior art turbulation system having a cooling passageway 10′ with a cooling fluid flowing in the direction 12′. As can be seen from this figure, a plurality of trip strips 14′ are arranged at an angle less than 90 degrees with respect to the flow direction 12′.
The contours 22 in the embodiments of FIGS. 1 and 2 illustrate areas of higher turbulence in the coolant flow field, and therefore more heat transfer pick-up. The heat transfer enhancement relative to channel flow with smooth walls is about two to three times the heat transfer obtained from the smooth channel flow depending on the Reynolds number for the coolant flow. The enhancement shown in FIGS. 1 and 2 is only local and washes away from its peak value either at the junction or apex 18 of the trip strips 14 and 16 in the chevron arrangement of FIG. 1 or close to the wall in an angled trip strip arrangement as shown in FIG. 2.
It is therefore desirable to extend the heat transfer regions that usually occur at the trip-strip junctions, either with other trip strips or connecting walls.